Added dynamic finders and Where Or

Added more finders in a list- 
YourModel::first();
YourModel::last();
YourModel::all();
YourModel::findBySql();
YourModel::findByUserNameAndIsAdmin(array('Admin', 'Yes'));
YourModel::findByUserNameOrIsAdmin(array('Sanjoy', 'Yes'));

Also Or Where condition added into the list.

->where($conditionsArray); // for multiple AND
->where($conditionsArray, '', 'OR');//for multiple OR